APA

Beckmann P., . (1971). A history of pi. New York: St. Martin's.

Chicago

Beckmann Petr, . 1971. A history of pi. New York: St. Martin's.

Harvard

Beckmann P., . (1971). A history of pi. New York: St. Martin's.

MLA

Beckmann Petr, . A history of pi. New York: St. Martin's. 1971.